The present invention relates to a cherry-dyeing agent and a dyeing solution for use in preparing cherries or cherry bobs (hereinafter referred to as "cherries") dyed red which have widely been used as, for instance, additives for confectionery such as cakes and jellies as well as a method for dyeing cherries with the dyeing solution.
Cherries have been dyed red with a dye prior to putting on the market or the use thereof. For instance, Japanese Unexamined Patent Publication (hereinafter referred to as "J.P. KOKAI") No. Sho 53-62856 discloses a technique for dyeing cherries red approximately identical to the natural color thereof using a naturally-occurring dye. More specifically, the method comprises the steps of boiling or steaming cherries to be dyed, immersing them in a mixed system which comprises carminic acid and/or laccaic acid as dyeing agents and an aluminum salt and an organic acid and/or a salt thereof as dyeing assistants and which has a pH ranging from 4 to 7 to maintain the pH value within the foregoing range and then immersing them in an acid or an aqueous solution of a mixture of an acid and a calcium salt and/or an aluminum salt to give cherries dyed red.
However, in this method, the preliminary process for boiling or steaming cherries to be dyed and the use of two baths for the immersion treatments are required. This makes the dyeing process quite troublesome. Further, the immersion treatments must be practically continued for a long time period (in general, 2 to 3 days). This results in a decrease of the production efficiency. Moreover, the cherries are excessively heated during boiling or steaming as well as other heat-treatments and, therefore, the texture of the cherries are softened and the taste thereof is likewise impaired.
On the other hand, Lecture H "Manufacture of Canned Foods", pp. 291-294, issued on September first, Showa 44 (1969), by Canners Association of Japan discloses a method for preparing cherries preserved in syrup which comprises dyeing cherries by immersing them in a dyeing solution comprising an artificial dye and an organic acid for adjusting pH thereof to 4.5 contained in a tub or tank, rapidly cooling them, then sufficiently washing with water, canning them together with syrup, degassing the contents of the can, i.e., the cherries and the syrup, sealing the can and sterilizing the contents of the sealed can.
However, this method dyes not only the fruit portion but also the carpophore thereof, provides cherry fruits whose color is quite different from that of the natural cherry fruit and, therefore, the commercial value of the resulting cherries is substantially damaged. Moreover, this method requires the use of a multistage immersion process and a water washing process and, thus the practice of this method is quite troublesome and further the taste of the resulting dyed cherries is also greatly impaired.